Electrical cabling is employed for a wide variety of purposes. For example, fiber optic cabling is often employed in communications networks, providing a physical medium for communication of voice or data information. Electrical cabling is also used to distribute power from central power stations to substations and ultimately to end users. In order to protect cabling from environmental conditions, the cabling is sometimes buried underground, with small enclosures arrayed along the length of the cabling. These enclosures are typically accessible via a surface aperture, with the aperture itself being protected with a manhole cover.
The use of the same reference symbols in different drawings indicates similar or identical items.